Mikaela Shiffrin charged from fifth to first on the second run to win the World Cup slalom in Schladming on Tuesday but could not stop Petra Vlhova clinching the discipline title.
Shiffrin, who returned from a bout of Covid-19 on Sunday, was in tears at the finish.
"Just crying a lot lately," she said at the start of a brief post-race interview.
The American struck a psychological blow in the last slalom before the Beijing Olympic and increased her lead over Slovakian Vlhova in the overall standings and secured the outright record for World Cup victories in a single discipline.
Vlhova, winner of five of the first six World Cup slaloms of the season, set the fastest time in the first run under lights in the Austrian Alps on Tuesday.
Shiffrin, the only woman to have beaten Vlhova in the slalom this season was 0.48sec back in fifth.
The race had been moved from Flachau because of the high rate of Covid-19 infection in the resort, some 25 kilometres to Schladming, which normally only hosts the men's slaloms.
Shiffrin rose to the challenge of a course that was steeper and longer than the regular stops on the women's circuit.
"It's such a privilege to race on this slope. All I wanted to do today was to earn that, to deserve it," said Shiffrin at the finish.
"It's iconic. It's Schladming. I was geeking out this morning. I can't believe that we can be here. It's quite special. It feels like it didn't happen."
After Shiffrin seized the lead in the second run, the final four skiers struggled to match her.
Neither Canadian Ali Nullmeyer nor Swiss Wendy Holdener, who had been tied for third, finished. Nullmeyer went flying halfway through her run on a course laid out by her own coach.
German Lena Duerr recorded only the 16th best second-run time, more than a second slower than Shiffrin, as she slipped from second to third.
Skiing last, Vlhova lost more than half a second to finish 0.15sec behind, but that ensured she would win the small crystal globe for slalom World Cup champion regaining a title she won in 2020.
Vlhova leads Shiffrin by 220 points in the slalom standings with only two World Cup races left.
Shiffrin, meanwhile, increased her lead over the Slovakian, the defending champion, to 55 points in the overall standings.
For Shiffrin, the victory was her 47th in a World Cup slalom, breaking a tie with the legendary Swede Ingemar Stenmark, who won 46 giant slaloms, for most in a single discipline.
Shiffrin said she was not thinking of records.
"Maybe I'll be able to answer that in one year or in five years," she said.